Gabal Abu Dabbab (ADAG) is located about 50 km northwest of Marsa Alam and represents as important site for the rare earths (REE), Zr, Nb, Y, Ta and Sn-bearing albite granite. The granite association is a highly lecucratic, albite-rich rocks with accessory columbite-tantalite, monazite, allanite, and zircon . Petrographically, the albite granite is composed mainly of albite, quartz and microcline-microperthite and muscovite, in association with accessories; cassiterite, tantalite-columbite, zircon, allanite apatite, corundum, ilmenite and monazite. Geochemically, the granite is enriched in Na2O, Al2O3, K2O, REEs, Ta and Nb, but it is poor in MgO, CaO, Fe2O3, TiO2, Ba and Sr. On plots, it is located within the field of alkali feldspar granite, display alkaline to highly fractionated calc-alkaline affinities and belong to peraluminous. The ADAG is characterized by enrichment of Na2O indicating the albitization process as well as Ta, Sn, Nb and Zr concentrations giving rise to rare metals-bearing albite granite and high Ga/Al ratios and low contents of Ba and Sr. It is anorogenic, in which Rb/Sr ratio is greater than unity and lie within plate regime. |
